IPT systems are well known. As discussed in international patent application WO 2010/090539, it is necessary in some IPT applications, such as electric vehicle charging, to provide a loosely coupled system capable of operating with a large air gap between the magnetic flux transmitting and receiving structures.
Due to the potential for large scale deployment of both stationary charging and roadway powered electric vehicle applications, magnetic flux transmitting and receiving structures that operate efficiently with minimum use of materials are highly desirable.
Apart from efficiency, another issue with loosely coupled systems is elimination or control of stray magnetic fields which may pose health risks, and which in most countries are required to be controlled within certain limits by law.